The headphone status indicators are located on the side of the right earcup.
Headphone status indicators (video included)
Bluetooth® indicator
Blue blinking: ready to pair
White blinking: connecting
White solid: connected
Battery indicator (while in use)
Green: full charge
Amber: medium charge
Red blinking: charge needed
Battery charge level (for iOS devices)
When connected to the Bose® SoundLink® On-Ear Bluetooth® headphones, iOS devices will display the headphone battery charge level near the upper right corner of the screen.